In present day computing and communications small form factor systems or platforms are enjoying increased popularity, including tablet devices, ultrabook computers, and other portable devices. Due in part to their small size, power in these systems (also referred to herein as “devices”) may typically be limited by the so-called skin temperature or chassis skin temperature of the system, such as the housing surface of a tablet device. Accordingly, the temperature limit for operating a semiconductor chip such as a general processor (CPU) within a small form factor system, which is also referred to as the maximum “junction temperature,” may not be a limiting factor during normal system operation. For example in typical portable devices in the ultrabook or tablet category, the maximum chassis skin temperature may be in the range of 40° C. or so while the maximum steady state junction temperature may be specified at 100° C.
A major benefit of some modern architectures that have large size of processor core components such as four or eight processor cores, is the ability to rapidly and on-demand boost processor and system performance. Such “turbo burst” capability allows a CPU and/or graphics processor unit (GPU) to burst to very high power for short periods of time, delivering a responsive system with enhanced user experience. Because the junction temperature time constants are much faster than those of the whole system the CPU/GPU junction temperature (also referred to herein generally as “TJ”), can in principle reach a TJ of 100° C. without violating the system skin temperature limit, which may specify a much lower temperature, as noted. However, controlling the CPU junction temperature to its steady state may significantly degrade the benefit provided by so-called turbo operation. On the other hand, some schemes that may permit a relatively higher Tj for operating CPU or GPU components require skin temperature sensors, relays and other components. This, however, adds to manufacturing complexity by creating a need to design CPU specifications based upon external devices such as controllers.
Accordingly, there may be a need for improved techniques and apparatus to solve these and other problems.